[0102] Various updates for Naxxramas

* Added movement waypoints to bosses Patchwerk (16028) and Grobbulus
(15931)
* Spawned GO Sapphiron Birth (181356)
* Adjusted size of Grobbulus (15931), Thane Korth'azz (16064), GO
Sapphiron Birth (181356)
  and spirit of each of the Four Horsemen
* Moved gameobject 181056 (Naxxramas) in Plaguewood above the ground
(was under the map)
* Removed duplicate spawn of GO 181575
* Fixed gameobject 181575 (Naxxramas Portal): players can now use it to
teleport after defeating boss Maexxna
* Allowed creature 16218 (Tesla Coil) to stand in the air
* Adjusted position of creatures 15954 (Noth the Plaguebringer) and
15936 (Heigan the Unclean)
* Added spawns for creatures 16194 (Unholy Axe), 16215 (Unholy Staff),
16216 (Unholy Swords) in Military Quarter
* Note: equipement model for these creatures need to be fixed
* Added spawns for rats in Naxxramas. Now, warriors can build up rage
before engaging mobs
* Set correct graveyard for players diing in Naxxramas
* Backported numerous missing gameobject from UDB (boss doors, portals,
cosmectics elements...)
  Sources: UDB v406 and YTDB